$ cat >> $HGRCPATH << EOF

  > [diff]

  > git = true

  > EOF

  $ hg init

  $ cat > foo << EOF

  > 0

  > 1

  > 2

  > 3

  > 4

  > EOF

  $ hg ci -Am init

  adding foo

  $ cat > foo << EOF

  > 0

  > 0

  > 0

  > 0

  > 1

  > 2

  > 3

  > 4

  > EOF

  $ hg ci -m 'more 0'

  $ sed 's/2/2+/' foo > foo.new

  $ mv foo.new foo

  $ cat > bar << EOF

  > a

  > b

  > c

  > d

  > e

  > EOF

  $ hg add bar

  $ hg ci -Am "2 -> 2+; added bar"

  $ cat >> foo << EOF

  > 5

  > 6

  > 7

  > 8

  > 9

  > 10

  > 11

  > EOF

  $ hg ci -m "to 11"

Add some changes with two diff hunks

  $ sed 's/^1$/ 1/' foo > foo.new

  $ mv foo.new foo

  $ sed 's/^11$/11+/' foo > foo.new

  $ mv foo.new foo

  $ hg ci -m '11 -> 11+; leading space before "1"'

(make sure there are two hunks in "foo")

  $ hg diff -c .

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -2,7 +2,7 @@

   0

   0

   0

  -1

  + 1

   2+

   3

   4

  @@ -12,4 +12,4 @@

   8

   9

   10

  -11

  +11+

  $ sed 's/3/3+/' foo > foo.new

  $ mv foo.new foo

  $ sed 's/^11+$/11-/' foo > foo.new

  $ mv foo.new foo

  $ sed 's/a/a+/' bar > bar.new

  $ mv bar.new bar

  $ hg ci -m 'foo: 3 -> 3+ and 11+ -> 11-; bar: a -> a+'

(make sure there are two hunks in "foo")

  $ hg diff -c . foo

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -4,7 +4,7 @@

   0

    1

   2+

  -3

  +3+

   4

   5

   6

  @@ -12,4 +12,4 @@

   8

   9

   10

  -11+

  +11-

  $ hg log -f -L foo,5-7 -p

  changeset:   5:cfdf972b3971

  tag:         tip

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     foo: 3 -> 3+ and 11+ -> 11-; bar: a -> a+

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -4,7 +4,7 @@

   0

    1

   2+

  -3

  +3+

   4

   5

   6

  changeset:   4:eaec41c1a0c9

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     11 -> 11+; leading space before "1"

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -2,7 +2,7 @@

   0

   0

   0

  -1

  + 1

   2+

   3

   4

  changeset:   2:63a884426fd0

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     2 -> 2+; added bar

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -3,6 +3,6 @@

   0

   0

   1

  -2

  +2+

   3

   4

  changeset:   0:5ae1f82b9a00

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     init

  diff --git a/foo b/foo

  new file mode 100644

  --- /dev/null

  +++ b/foo

  @@ -0,0 +1,5 @@

  +0

  +1

  +2

  +3

  +4

With --template.

  $ hg log -f -L foo,5-7 -T '{rev}:{node|short} {desc|firstline}\n'

  5:cfdf972b3971 foo: 3 -> 3+ and 11+ -> 11-; bar: a -> a+

  4:eaec41c1a0c9 11 -> 11+; leading space before "1"

  2:63a884426fd0 2 -> 2+; added bar

  0:5ae1f82b9a00 init

  $ hg log -f -L foo,5-7 -T json

  [

   {

    "rev": 5,

    "node": "cfdf972b3971a2a59638bf9583c0debbffee5404",

    "branch": "default",

    "phase": "draft",

    "user": "test",

    "date": [0, 0],

    "desc": "foo: 3 -> 3+ and 11+ -> 11-; bar: a -> a+",

    "bookmarks": [],

    "tags": ["tip"],

    "parents": ["eaec41c1a0c9ad0a5e999611d0149d171beffb8c"]

   },

   {

    "rev": 4,

    "node": "eaec41c1a0c9ad0a5e999611d0149d171beffb8c",

    "branch": "default",

    "phase": "draft",

    "user": "test",

    "date": [0, 0],

    "desc": "11 -> 11+; leading space before \"1\"",

    "bookmarks": [],

    "tags": [],

    "parents": ["730a61fbaecf426c17c2c66bc42d195b5d5b0ba8"]

   },

   {

    "rev": 2,

    "node": "63a884426fd0b277fcd55895bbb2f230434576eb",

    "branch": "default",

    "phase": "draft",

    "user": "test",

    "date": [0, 0],

    "desc": "2 -> 2+; added bar",

    "bookmarks": [],

    "tags": [],

    "parents": ["29a1e7c6b80024f63f310a2d71de979e9d2996d7"]

   },

   {

    "rev": 0,

    "node": "5ae1f82b9a000ff1e0967d0dac1c58b9d796e1b4",

    "branch": "default",

    "phase": "draft",

    "user": "test",

    "date": [0, 0],

    "desc": "init",

    "bookmarks": [],

    "tags": [],

    "parents": ["0000000000000000000000000000000000000000"]

   }

  ]

With some white-space diff option, respective revisions are skipped.

  $ hg log -f -L foo,5-7 -p --config diff.ignorews=true

  changeset:   5:cfdf972b3971

  tag:         tip

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     foo: 3 -> 3+ and 11+ -> 11-; bar: a -> a+

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -4,7 +4,7 @@

   0

    1

   2+

  -3

  +3+

   4

   5

   6

  changeset:   2:63a884426fd0

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     2 -> 2+; added bar

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -3,6 +3,6 @@

   0

   0

   1

  -2

  +2+

   3

   4

  changeset:   0:5ae1f82b9a00

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     init

  diff --git a/foo b/foo

  new file mode 100644

  --- /dev/null

  +++ b/foo

  @@ -0,0 +1,5 @@

  +0

  +1

  +2

  +3

  +4

Regular file patterns are allowed with -L and their diff shows all lines.

  $ hg log -f -L foo,5-7 -p bar

  changeset:   5:cfdf972b3971

  tag:         tip

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     foo: 3 -> 3+ and 11+ -> 11-; bar: a -> a+

  diff --git a/bar b/bar

  --- a/bar

  +++ b/bar

  @@ -1,4 +1,4 @@

  -a

  +a+

   b

   c

   d

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -4,7 +4,7 @@

   0

    1

   2+

  -3

  +3+

   4

   5

   6

  changeset:   2:63a884426fd0

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     2 -> 2+; added bar

  diff --git a/bar b/bar

  new file mode 100644

  --- /dev/null

  +++ b/bar

  @@ -0,0 +1,5 @@

  +a

  +b

  +c

  +d

  +e

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -3,6 +3,6 @@

   0

   0

   1

  -2

  +2+

   3

   4

Option --rev acts as a restriction.

  $ hg log -f -L foo,5-7 -p -r 'desc(2)'

  changeset:   2:63a884426fd0

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     2 -> 2+; added bar

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -3,6 +3,6 @@

   0

   0

   1

  -2

  +2+

   3

   4

  changeset:   0:5ae1f82b9a00

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     init

  diff --git a/foo b/foo

  new file mode 100644

  --- /dev/null

  +++ b/foo

  @@ -0,0 +1,5 @@

  +0

  +1

  +2

  +3

  +4

With several -L patterns, changes touching any files in their respective line

range are show.

  $ hg log -f -L foo,5-7 -L bar,1-2 -p

  changeset:   5:cfdf972b3971

  tag:         tip

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     foo: 3 -> 3+ and 11+ -> 11-; bar: a -> a+

  diff --git a/bar b/bar

  --- a/bar

  +++ b/bar

  @@ -1,4 +1,4 @@

  -a

  +a+

   b

   c

   d

  diff --git a/foo b/foo

  --- a/foo

  +++ b/foo

  @@ -4,7 +4,7 @@

   0

    1